Abstracts and presentations are embargoed for release at date and time of presentation or time of AHA/ASA news event. Failure to honor embargo policies (http://newsroom.heart.org/newsmedia/embargo-policy) will result in the abstract being withdrawn and barred from presentation.

Jump to

Abstract

Introduction: Single right ventricle (SRV) myocardial fiber architecture may not be efficient in generating ventricular twist, hence ventricular suction. Intraventricular pressure difference (IVPD) is responsible for efficient ventricular filling. Apical IVPD is postulated to reflect of ventricular suction. This study utilizes IVPD to compare SRV and SLV through surgical stages for insights into single ventricle filling hemodynamics.

Methods: Cross sectional study of prospectively recruited SRV and SLV patients. Functional echo was performed at pre-Norwood, S0; pre-Glenn, S1; pre-Fontan, S2 and post-Fontan, S3, including color m-mode of the systemic valve inflow. IVPD was calculated using MATLAB with Euler’s equation and averaged over 3 heart beats. IVP gradient (IVPG) was calculated from IVPD divided by LV length. IVPG was further separated at mid ventricle to yield basal IVPG and apical IVPG. We also measured time to peak IPVD and E wave, and filling time normalized to R-R interval. Data is expressed as median (interquartile ranges). Within and between group difference was tested using ANOVA with Tukey post hoc test for multiple testing.

Results: There was 58 SRV and 52 SLV with >10 patients at each surgical stage. Within SRV, IVPG did not change across surgical stages. Within SLV, IVPG was lower at S2 and S3 when compared to S0 (p<0.01), basal IVPG was lower at S2 (p=0.01) and apical IVPG lower at S2 and S3 when compared to S0 (p<0.02). No significant difference between SRV and SLV IVPG, basal or apical IVPG at each surgical stage. Time to peak IVPD, timing of E and normalized filling time were not significantly different.

Conclusions: Despite inherent difference in myocardial fiber architecture, SRV apical IVPG was similar to SLV suggesting no difference in ventricular suction. Observed changes in SLV IVPG in later stages is likely a function of ventricular unloading. No evidence of relative impairment in SRV diastolic performance was found when compared to SLV.